Statistics

The text has an extensive discussion of probabilities.  This course is concerned with the basic understanding of probability and it's applications.  For this week you may select any one the exercises listed as 1 to 5 below.  You may repeat an exercise that has been selected by another classmate.  The goal is to learn and you get back what you put in. Include the question number and last name in the title of the posting.

  Briefly state the question and use the Equation Editor to present all equations clearly.

For probability questions, define events as:

A: drawing a 10♣

B: drawing a 9♥

P(A&B) = P(A)P(B|A) = ??

Special Exercises (1to 5)

 1. What is the probability of drawing at random the 4♥ and the 9♣ from a deck of cards on two successive draws? Use Insert/Insert symbol to get the heart, club, diamond,spade symbol by selecting the drop down menu to the left of Paragraph.  Also, click on the drop down menu next to the Black Square icon in the menu of the Editor to change colors of the characters. 

2. 18 people were poled and 10 said they have shopped at Wal-Mart and 8 said they have shopped at Target. 4 said they shopped at both. What is the probability that the group shopped at Wal-Mart or Target?.  

3. Define independent and mutually exclusive events mathematically by using P(A) & P(B) for events A & B.  

4. What is the probability of randomly drawing a 10 or a ♦  from a deck of cards?

5. What are the total possible outcomes of rolling a pair of dice? Note that the pair 3,4 is not the same as the pair 4,3. What is the probability of rolling a 7 with a pair of dice? P(7) = No. of successful outcomes/Total No. of outcomes

In questions 1,2,4, begin by clearly defining events A & B as shown below.

 For example, A: 4♥ and B:  9♣.  State  P(A)=??, P(B)=?? and then apply the appropriate equations , such as

P(A&B) = P(A)P(B|A) or  P(AorB) = P(A)+P(B)-P(A&B)

Substitute values and compute the answer. I urge you to read the attachments in the Videos-Topics In Stat 230/Probability Rules.

I prefer to use P(A&B) or P(AorB) instead of P(A∩ B) or P(A∪ B). You will see the latter on the final so be sure you know what the "∩ " and  "U" symbols mean.